Blending apparatus



United States Patent [72] Inventor Robert R-GOIHS 3,167,306 1/1965Clark. 259/4 Bartlesville, Oklahoma 3,275,303 9/1966 Goins 259/95 211Appl. No. 781,}92l9 8 3,317,191 5 1967 Brown 259/4 [22] Filed Dec. 6 4sPatented Nov. 10, 1970 ZZZ? z ffg i [73] Assignee Phillips PetroleumCompany ney g n ulgg a corporation of Delaware [54] BLENDING APPARATUS6Claims3Drawing Figs ABSTRACT: Blendmg apparatus 1s formed by an uprlghtchamber having an inlet 1n the upper reglon and a plurahty of U.S.utlets in the bottom A plurality of elongated tubes extend in 259/95 agenerally vertical direction inside the chamber, with the I] Int. ClB0lfl5/02 [ower d of th tub extending through respective outlets. Fleldof Search Deflecting means are positioned in the bottom of the chamber36, to form a plurality of channels to direct material to be blended 56R f d downwardly toward the tubes. The tubes are provided with I Ieerences openings adjacent the outlets to receive material flowingUNITED STATES PATENTS through the channels and to convey such materialout of the 3,138,369 6/1964 Bennett 259/ chamber.

ss 33 2e 3| 1 P1 1 1h F II l I I I I I I I l I II I I 1 I 1 I 1 I 1 I II I I I I L3 1 1 I I I 1 10 I I I I I l I I I I I l l I I I so I I 124*1.) I I I I I l I l I I l l l 1 I l 1 l I 1 I I I 1 l I l I I I I l lan I 1 1 i 1 1 1 1 I 22 13K '11 I9 IB' --X Sheet 1 of 2 INVENTOR. R. R.GOINS A T TORNEVS Patented Nov. 10, 1970 Sheet 2 012 FIG. 2

INVENTOR- R. R. GOINS kw Q m A T TORNEVS BLENDING APPARATUS In variousindustrial operations, it is desirable to mix solid particulatematerials to obtain uniform blends. For example, it is common in theplastics industry to produce polymers in the form of relatively smallpellets and to blend these pellets from different production runs inorder to beassured of a uniform product. It has recently been discoveredthat particulate materials of this type can be blended quite effectivelyby the use of blending tanks which have a plurality of gravity flowtubes positioned therein. The tubes are provided with a plurality ofopenings to receive particulate material disposed in the blendingchamber and to convey the material to a common collection chamber. Anumber of devices of this general type have become known in the art, asexemplified by U.S. Pat. Nos. 3,138,369; 3,2l6,629; and 3,275,303.

The present invention is directed toward providing improved apparatus ofthe general type described in the abovementioned patents. In accordancewith this invention, the bottom region of the blending tank is providedwith a plurality of deflecting means to direct particles downwardlytoward the flow tubes which extend through the bottom of the vessel. Theflow tubes are provided with one or more openings adjacent the outletsof the vessel to receive the downwardly flowing material. This assures apositive drain of all particles from the bottom of the blending vessel,thereby eliminating the possibility of particles accumulating inrecesses in the lower region of the vessel.

Accordingly, it is the object of this invention to provide improvedapparatus for use in blending materials.

The accompanying drawing illustrates a specific embodiment of theapparatus of this invention.

FIG. 1 is an elevation view, shown partially in section, ofthe blendingapparatus.

FIG. 2 is a view along line 2-2 in FIG. 1.

FIG. 3 illustrates a modification of the apparatus of FIG. 1 in which aflow diverter is secured to one of the flow tubes.

Referring now to the drawing in detail, there is shown an uprightblending vessel which is provided with a top closure member 11. Closuremember 11 is provided with one or more access openings, such as 12 and13, through which materials to be blended can be introduced. A pluralityof hollow tubes 14 are positioned within vessel 10 so as to extendgenerally parallel to the vertical axis of the vessel. The lower ends ofthese tubes extend through openings in the bottom of vessel 10 and areconnected to tubes 15 which communicate with a collection vessel 16. Anoutlet conduit 17 extends from vessel 16, and is provided with a starvalve or other flow control means 18.

In accordance with this invention, a plurality of deflecting means 19are provided in the lower region of vessel 10. As illustrated, six suchdeflecting means are provided, one for each of the flow tubes. Eachdeflecting means is formed by three generally triangular shaped plates20, 21 and 22. As illustrated in FIG. 2, the upper edge of plate 20 issecured to the lower end of vessel 10. Plates 21 and 22 are secured toone another and to plate 20. The lower edges of the three plates contacttube 14, thereby providing an outlet opening through which the tubeextends. Although generally flat plates are normally preferred in orderto simplify construction, it is possible to construct the deflectingmeans so as to provide a generally conical configuration. All that isrequired is that wells or channels be provided to direct the particlesof material to be blended downwardly and inwardly to flow tubes 14. Inthe illustrated embodiment, deflecting means 19 actually constitutes thebottom of vessel 10. In some constructions, these deflecting means canform a false bottom if vessel 10 is provided with a conventional bottom.As illustrated in FIG. I, each of the tubes 14 is provided with one ormore openings 23 adjacent the bottom openings in vessel 10. Theseopenings permit material within vessel 10 to enter the tubes and beremoved from the bottom of the vessel. It is important that openings 23be of such size and shape that there is no hold-up of particles in thebottom of vessel 10. In general, a plurality of openings 23 are formedin each tube and cover substantially all of the circumference of eachtube at the bottom region.

In addition to thejopenings 23 which are located adjacent the bottom'ofvessel 10, each of the tubes 14 is provided with one or more additionalopenings 24 which are located at spaced intervals through vessel 10.Openings 24 permit the material being blended to enter the tubes atvarious elevations, which greatly facilitates uniform mixing. Openings24 can be of various configurations, several examples of which are shownin the patents mentioned above. The spacings of these openings can bevaried in any desired manner to provide uniform mixing of thematerial tobe blended.

The material to be blended is introduced into vessel 1 through one orboth of the openings 12 and 13. For example, a conduit 26communicateswith opening 13 to provide for the introduction of the material from asource, not shown. The particles to be blended flow into vessel 10 andare withdrawn through tubes 14 when valve 18 is opened. This withdrawalcan take place during the time that particles are introduced into thevessel, or can take place after vessel 10 is filled or partially filledwith a charge of particles. In some operations, a single pass throughthe mixing vessel is all that is required to provide the desired degreeof mixing. In this situation, the blended pellets are withdrawn throughan outlet conduit 27 by opening valve 28 therein.

In other operations, it is desirable to recirculate the pellets throughthe blender one or more times. This can be accomplished by means of aconduit 30 which extends from conduit 17 to the inlet of a cycloneseparator 31. The bottom outlet-oz" separator 31 is connected by aconduit 32 to opening 12. The bottom outlet of separator 31 is, ofcourse, physically positioned above opening 12 in actual practice sothat the particles move by gravity from separator 31 to opening 12. Avent conduit 33 also communicates with opening 12. Conduit 36 isprovided with a valve 34 to control the flow to separator 31. A bypassconduit 35, which has a valve 36 therein, extends from conduit 30 toopening 13. Valves 34 and 36 can be replaced by a conventional divertervalve so that the flow path can be controlled by a single valve. Aconduit 37, which has a valve 38 therein, extends from conduit 30 to asource of pneumatic pressure, not shown. When valve 38 is opened, thepneumatic pressure carries pellets from conduit 17 through conduit 30 toseparator 31 and to opening 12 or 13, depending on the positions ofvalves 34 and 36. In either event, the pellets are returned to the topof vessel 10. If the flow is through separator 31, the transporting gasis removed and withdrawn through an outlet conduit 40. If the flow isdirected to opening 13, the transporting gas is removed from the systemthrough conduit 33. The pellets can be recirculated through the vessel10 as many times as is required toprovide a uniform blend.

In the blending of certain types of materials, a more uniform blend canbe obtained by the addition of baffle means 41 to tubes 14 aboveopenings 23, as illustrated in FIG. 3. This baffle means canadvantageously be in the form of two conical sections which are securedto the tube in the manner illustrated and which serve to divert the flowof particles downwardly toward the deflecting means provided by plates20, 21 and 22.

Tubes 14 can be provided with one central longitudinal passage or with aplurality of such passages. The latter can be accomplished by insertinga baffle 42 in the tubes, as shown in FIGS. 2 and 3. This baffle candivide the tube into two or more passages, thereby effectivelyincreasing the number of tubes in vessel 10. Openings 24 can be at thesame or different levels with respect to the plurality of passages ineach tube. In general, there should be as many openings 23 in each tubeas there are passages within the tube to assure uniform draining fromeach of the deflecting means 19.

While this invention has been described in conjunction with presentlypreferred embodiments, it obviously is not limited thereto.

lclaim:

1. Blending apparatus comprising:

a chamber having at least one opening in the top portion thereof and aplurality of openings in the bottom, the latter being spaced from oneanother;

a plurality of elongated tubes positioned within said chamber so as toextend generally parallel to the vertical axis of the chamber, the lowerend of each of said tubes extending through a respective one of theopenings in the bottom of said chamber, each of said tubes having atleast one opening in the side thereof at a location above and closelyspaced to the opening in the bottom of the chamber through which thetube extends; and plurality of deflecting means in the bottom of saidchamber. each of said deflecting means having walls which engage arespective tube at a region below and closely spaced to said at leastone opening in the tube and which extend upwardly and outwardlytherefrom so as to provide a channel receive material to be blendedwhich is positioned within said chamber and to direct such materialdownwardly toward the tube and into said at least one opening in thetube.

2. The apparatus of claim 1 wherein each of said deflecting meanscomprises three generally triangularly shaped plates.

3. The apparatus of claim 1 wherein at least one of said tubes containsa-baffle which extends longitudinally of the tube so as to divide thetube into a plurality of passages which extend longitudinally of thetube. said tube being provided with a plurality of said openings so thatat least one of said openings communicates with each of said passages.

4. The apparatus of claim 1, further comprising a collecting means,means connecting the lower ends of said tubes with said collectingmeans, and conveying means extending from said collecting means to saidopening in the top portion of said chamber to permit material to beblended to be passed from said collecting means into said chamber.

5. The apparatus of claim 1, further comprising baffle means secured toeach of said tubes adjacent said deflecting means so as to divertparticles flowing downwardly through said chamber adjacent the tubesoutwardly away from the tubes toward the walls of said deflecting means.

6. The apparatus of claim 5 wherein each of said baffle means comprisestwo frustoconically shaped members surrounding said tubes with the basesthereof joined together.

UNITED STATES PATENT OFFICE CERTIFICATE OF CCRRECTIGJ Patent No.3,539,151; Robert R. Goina Dated Nov It is certified that error appearsin the above-identified patent and that Letters Patent are herebycorrected as shown below:

Column 3, line 11;, "to" has been omitted after "channel".

sacs-an m SEALED m2 197! EMILHWR mm E. W Anesfing Offieer commissionerof Pa

